During his entire life, Konrad Duden strove toward the unification and simplification of the German orthography. His 1880 dictionary marks the start of the Duden series, which included 28,000 words on 187 pages on it's first edition. In 1902, the German parliamentary upper house declared his rules for orthography mandatory in official state documents. Austria, Hungary and Switzerland followed. One hundred years after his death, the Duden dictionary keeps it's beacon as the authoritative source for German orthography. (Source: Wikipedia)